(5) OFF-PULL TEST switch. When turned
display. the remote KAC 952 power amplifier/antenna
clockwise. turns set on. When pulled out, provides for
coupler and KTR 953 receiver/exciter. The system
manual squelch control.
operates on any 0.1 kHz frequency between 2.000 and
(6) Frequency transfer button.
active and standby frequencies.
With the capability to preset and store 99
frequencies for selection during flight, the system also
c. Mode of Operation.
allows for selection of other frequencies manual (direct
tuning). or reprogramming of any preset frequency. The
(1) Frequency mode. In the frequency mode
system automatically matches the antenna by keying the
of operation frequencies are entered into the STBY
microphone. Power to the system is routed through a
window of the display and may then be transferred into
25-ampere circuit breaker. placarded HF, located on the
the USE window by pressing the frequency transfer
copilot's circuit breaker panel.
button. To select frequencies the MHz portion of the
frequency displayed in the STBY window is incremented
b. Controls and Functions .
or decremented in 1 MHz steps by rotating the MHz
knob either clockwise or counterclockwise.
frequencies will roll over or roll under at each band edge
(118 or 135 MHz). The kHz portion of the frequency
(2) Mode display. Displays LSB, AM or USB
displayed in the STBY window may be incremented or
mode of operation as selected.
decremented by rotating the 25 kHz knob either
(3) CHANNEL display. Displays from 1 to 99
clockwise or counterclockwise. Frequency selection is in
channels as selected.
50 kHz steps when the 25 kHz knob is pushed in and is
(4) Light sensor.
The light sensor is a
in 25 kHz steps when the 25 kHz knob is pulled out.
photocell which automatically adjusts brightness of the
Frequencies roll over from 95 or 97 to 00 and roll under
from 00 to 95 or 97 according to the position of the 25
(5) MODE switch. The mode switch is a
kHz knob. Frequencies are transferred from STBY to
momentary pushbutton switch that selects LSB, AM or
USE window and vice versa by depressing the
USB modes of operation.
frequency transfer button.
(6) FREQ/CHAN switch. Transfers the HF
system from a direct frequency operation to a
d. Operating Procedures.
channelized form of operation.
(7) PGM (program) recessed switch
1. AVIONICS MASTER switch -ON.
channelized data to be modified. The PGM message
2. OFF-PULL TEST switch -Turn
will be displayed whenever this switch is depressed.
clockwise out of detent.
frequencies displayed will be those
(a) Program. The program mode must
be used for setting or changing any of the 99 preset
3. Audio select button (audio control
frequencies. Each of the 99 channels may be preset to
panel) - Select as required.
receive and transmit on separate frequencies (semi-
4. OFF-PULL TEST switch -Pull out
duplex). receive only. or transmit and receive on the
and rotate until the desired audio
same frequency (simplex). The operating mode (LSB,
level is obtained. Push the knob
USB or AM) must be the same for both receive and
back in to activate the automatic
transmit and can also be preset.
(8) Frequency/channel selector. This selector
5. Active frequency - Insure desired
consists of two concentric knobs that control the channel
active frequency is displayed in USE
and frequency digits. plus the lateral position of the
6. Microphone switch - Press to
(a) Frequency control. The outer knob
becomes a cursor (flashing digit) control with the
e. Shutdown Procedure. Turn OFF-PULL TEST
FREQ/CHAN switch in the FREQ position. The flashing
switch counterclockwise to the OFF position.
digit is then increased/decreased with the inner knob.
(b) Channel control. The outer knob is
3-11. HF Communication Set (KHF 950).
not functional when the FREQ/CHAN switch is in the
CHAN position. The inner knob will provide channel
a. Description. The KHF 950 HF system consists
control from 1 through 99, displayed at the right end of
of three units; the pedestal mounted KCU 951 control
the display window.
Change 5 3-9